Rates and routes of trace element uptake in zebra mussels

Abstract

The zebra mussel, Dreissena polymorpha, a nonindigenous invasive species, is now widespread throughout the eastern half of North America. Because zebra mussels are ubiquitous and because they effectively filter particulate matter out of suspension, the cycling and residence times of particle-reactive metals will likely be affected in waters with zebra mussels. This study describes experiments designed to assess the possibility of using this species as a bioindicator of metals in ambient freshwater environments. Laboratory exposures of zebra mussels to 110m Ag, 109 Cd, 51 Cr, 14 C, 203 Hg, and 75 Se were employed to measure their assimilation efficiencies (percentage of ingested element that crosses gut lining) from eight food types (four algal species and bacteria, seston, and mineral assemblages), absorption efficiencies from water (percentage of element pumped by the mussel that is absorbed by the animal), and rates of depuration of these elements from mussels following long-term exposures to food and water. Assimilation efficiencies of elements from foods ranged from 4 to 29% for silver (Ag), 19 to 72% for cadmium (Cd), 42 to 85% for carbon (C), 2 to 19% for chromium (Cr), 4 to 40% for mercury (Hg), and 8 to 46% for selenium (Se). Absorption efficiencies from the dissolved phase were 1.87% for Ag, 1.02% for Cd, 0.47% for Cr(III), 0.27% for Cr(VI), 1.17% for Hg, and 0.03% for Se. Efflux rate constants (d Ϫ1 ) following long-term exposure to food and water were 0.067 and 0.084 for Ag, 0.013 and 0.011 for Cd, 0.019 and 0.011 for Cr, 0.050 for Hg (food only), and 0.026 and 0.035 for Se. These loss rates corresponded to biological half-lives ranging from 8 d for Ag to 76 d for Se. Loss rates of trace elements from zebra mussel feces followed the following sequence: Cr Ͻ Ag Ͻ Se Ͻ Hg Յ Cd, with average retention half-times being 59, 43, 11, 6.7, and 5.1 d, respectively, which indicates that geochemical cycling rates from zebra mussel biodeposits are element specific. Egestion patterns of the radioisotopes indicated two digestive phases, extracellular and intracellular digestion. The extent of intracellular digestion ranged from 7 to 40%, depending on the food source, and correlated with assimilation efficiency for Ag, Cd, and Hg. The bioaccumulation parameters measured for D. polymorpha can be used in kinetic models to quantify the relative importance of food and water as sources of metals and to predict on a site-specific basis the tissue concentrations of metals in these mussels, as shown for Cd. Because D. polymorpha accumulates metals from dissolved and particulate sources in proportion to ambient concentrations, this species can be an effective bioindicator of freshwater metal contamination.

To what extend the dam dredging can influence the background level of metals in the Rhine River: using chemical and biological long-term monitoring to answer

“…3). These results confirm the ability of zebra mussels to actively regulate metals and to excrete them from their tissues (Roditi and Fisher, 1999;Bourgeault et al, 2011). Besides, these results highlight that the dredging operation had a transient effect on caged mussels when considering both metal bioaccumulation and mortality.…”

Exchange rates of cadmium between a burrowing mayfly and its surroundings in nature

“…5 to estimate the biological half-life (t ½ ) of Cd, which is ϳ1 week for the whole insect and its constituent parts (Table 1). The value of the Cd loss rate constant k E (Table 1) for whole H. limbata (0.09 d Ϫ1 ) is similar to, but somewhat lower than, those reported for copepods (0.1-1.3 d Ϫ1 ) (Wang and Fisher 1998;Xu et al 2001) and higher than those reported for bivalves (0.01-0.03 d Ϫ1 ) (Roditi and Fisher 1999;Chong and Wang 2001) and gastropods (0.001-0.005 d Ϫ1 ) (Wang and Ke 2002). The values of the loss rate constants for the gut and body portions that we measured in our field study (0.11 and 0.13 d Ϫ1 , respectively) are similar to those reported from a laboratory study on Hexagenia rigida (0.10 and 0.09 d…”

Effects of salinity, temperature and food type on the uptake and elimination rates of cd, cr, and zn in the asiatic clamcorbicula fluminea

“…The assimilation efficiencies of Cd associated with algae (70~90%) and sediment (40~65%) in C. fluminea were generally higher than the respective AEs in bivalves including cases involving various sediment-dwelling clams (Macoma balthica, Potamocorbula amurensis and Ruditapes philippinarum) and mussels (Dreissena polymorpha, M. edulis and Perna viridis) from previous studies (Roditi and Fisher 1999;Lee and Luoma 1998;Chong and Wang 2000;Ke and Wang 2001).…”

“…A relatively small fraction of metals was present in the form of cytosolic form in algalpoor suspended particles and sediments (Lee and Luoma 1998). Similarly, the nutritional quality of food might influence the AEs of metals as well as the AE of carbon in the food (Roditi and Fisher 1999).…”